Update JRuby versions for testing in travis-ci
Update JRuby versions for testing in travis-ci

The RVM alias jruby-19mode is outdated (JRuby 1.7.19)
JRuby 9.1 is the active branch
JRuby 1.7 is maintained with no EOL announced
sparklemotion/mechanize,eligoenergy/mechanize,flavorjones/mechanize,eligoenergy/mechanize,sparklemotion/mechanize